The objective of this study is to test the hypothesis that steroid abnormalities contribute to the accelerated development of atherosclerosis in some patients with diabetes mellitus. Patients in four groups will be studied. Diabetics with coronary atherosclerosis documented by coronary angiography will be compared to diabetics without significant coronary disease and to non-diabetic patients with and without coronary atherosclerosis. Nineteen steroids secreted by the adrenal or gonads or resulting from peripheral metabolism and secretion will be measured in the baseline state. ACTH will also be measured. Dose response curves of the effect of ACTH, dexamethasone, cortisol and metyrapone on steroidal concentrations will allow assessment of the regulatory mechanism of the hypothalamic-pituitary-adrenal axis.